Rozhen Observation Calendar

Which nights are best for a target over the coming weeks. The astronomy mark (darkness × altitude × Moon) is computed for every night; the weather and the overall mark exist only where Open-Meteo has a forecast (the next four days) or ERA5 history (past nights) — the rest is honestly blank.

Best nights for 3C 273: 11-19 (20), 11-18 (18), 11-17 (16), 11-16 (14), 11-15 (12) — by astronomy; check the weather when the night is within four days.

2036-10-21astronomy score per night — click a bar for that night2036-11-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-10-21 Tue	0	—	unknown	—	50.2° 11:45	10.1	7%	54.1°
2036-10-22 Wed	0	—	unknown	—	50.2° 11:45	10.14	14%	67.3°
2036-10-23 Thu	0	—	unknown	—	50.2° 11:40	10.18	21%	80.0°
2036-10-24 Fri	0	—	unknown	—	50.2° 11:35	10.22	30%	92.4°
2036-10-25 Sat	0	—	unknown	—	50.2° 10:30	10.26	39%	104.6°
2036-10-26 Sun	0	—	unknown	—	50.2° 10:25	10.3	49%	116.6°
2036-10-27 Mon	0	—	unknown	—	50.2° 10:25	10.34	58%	128.4°
2036-10-28 Tue	0	—	unknown	—	50.2° 10:20	10.37	67%	140.3°
2036-10-29 Wed	0	—	unknown	—	50.2° 10:15	10.41	76%	152.2°
2036-10-30 Thu	0	—	unknown	—	50.2° 10:10	10.45	83%	164.2°
2036-10-31 Fri	0	—	unknown	—	50.2° 10:05	10.49	90%	176.4°
2036-11-01 Sat	0	—	unknown	—	50.2° 10:05	10.52	95%	171.0°
2036-11-02 Sun	0	—	unknown	—	50.2° 10:00	10.56	98%	158.3°
2036-11-03 Mon	1	—	unknown	—	50.2° 09:55	10.59	100%	145.3°
2036-11-04 Tue	1	—	unknown	—	50.2° 09:50	10.63	99%	132.0°
2036-11-05 Wed	1	—	unknown	—	50.2° 09:50	10.66	96%	118.5°
2036-11-06 Thu	1	—	unknown	—	50.2° 09:45	10.7	90%	104.8°
2036-11-07 Fri	1	—	unknown	05:25–05:30 (marginal, 0.08 h)	50.2° 09:40	10.73	83%	90.9°
2036-11-08 Sat	2	—	unknown	05:25–05:30 (marginal, 0.08 h)	50.2° 09:35	10.76	73%	76.9°
2036-11-09 Sun	2	—	unknown	05:25–05:30 (marginal, 0.08 h)	50.2° 09:30	10.79	63%	62.9°
2036-11-10 Mon	2	—	unknown	05:20–05:35 (marginal, 0.25 h)	50.2° 09:30	10.83	52%	48.7°
2036-11-11 Tue	3	—	unknown	05:10–05:35 (marginal, 0.42 h)	50.2° 09:25	10.86	40%	34.6°
2036-11-12 Wed	5	—	unknown	05:05–05:35 (marginal, 0.5 h)	50.2° 09:20	10.89	29%	20.5°
2036-11-13 Thu	7	—	unknown	05:00–05:35 (marginal, 0.58 h)	50.2° 09:15	10.92	20%	6.4°
2036-11-14 Fri	9	—	unknown	05:30–05:35 (good, 0.08 h)	50.2° 09:10	10.95	12%	7.7°
2036-11-15 Sat	12	—	unknown	05:25–05:40 (good, 0.25 h)	50.2° 09:10	10.98	5%	21.7°
2036-11-16 Sun	14	—	unknown	05:20–05:40 (good, 0.33 h)	50.2° 09:05	11.0	2%	35.4°
2036-11-17 Mon	16	—	unknown	05:15–05:40 (good, 0.42 h)	50.2° 09:00	11.03	0%	49.0°
2036-11-18 Tue	18	—	unknown	05:10–05:40 (good, 0.5 h)	50.2° 08:55	11.06	1%	62.2°
2036-11-19 Wed	20	—	unknown	05:05–05:40 (good, 0.58 h)	50.2° 08:55	11.08	4%	75.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-10-21&days=30"
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&days=30&format=csv" -o m31-calendar.csv

One row per night: score_astronomy always, score_weather / score only where a forecast or history exists (null otherwise, with weather_source saying which), best window, dark hours, Moon illumination and separation, transit. 7–60 nights. Errors: 400 with invalid_date or target_unresolved. Results are cached for six hours; calculation version 2026-10-10.1.